People commit armed robberies with toy guns on a fairly regular basis.
OK. I won't argue with that.
It remains a fact that I DOUBT he had ill intent. ( "I Doubt" is the fact)
He may well have a problem with violating carry law unless he was carrying a fishing pole.
I'm not going to imagine him another "Sandy Hook Killer" without some probable cause. I'm keeping my blood pressure under control.
I CAN understand the OP looking for info and being concerned. (Child in school)
Its not unusual for me to transport a gun project. IMO, amongst my gun circle, its good to consolidate the collection of tools and spares at one location. Your house,my house,doesn't matter. The roll pin punches,fixtures,barrel nut wrenches, vise jaws, headspace gauges,etc. All collocated.
I own many of the tools and parts but they are in a toolbox at someone elses house. I have a motor vehicle and I transport discretely.
I can relate enough that I don't project "mass murderer" on some indiscrete dilrod walking his AR project someplace. We can walk to our local gunsmith.
A few years back the fad was "Open Carry Activists' shopping for Oreos at Walmart carrying AK;s and AR's,or going to breakfast at the local cafe armed with long guns or just taking a road walk or to Little League Games.
These efforts had quite a bit of support here on TFL. (Not Mine)
While I could see the point of "normalizing" carry, I do not support stirring the citizens to call for more laws. IMO,low key is good.
There may be more to this story, but with what we have,,, I'd say the guy needs a lecture from the Cops ...."tuneup" If he checks out "not crazy" give him his AR back. "Go,and sin no more"